getting started: update summary page

Provide backgound on what Golioth is all about and describe what is found in
thie getting started guide.

Signed-off-by: Mike Szczys <mike@golioth.io>

docs/getting-started/getting-started.md

@@ -0,0 +1,41 @@
+---
+title: Getting Started
+sidebar_position: 0
+---
+
+## What is Golioth?
+
+![Console](./assets/console.png)
+
+Golioth is an IoT platform optimized for the developer experience. We provide a
+single control plane for all of your devices.
+
+### Cloud Side
+
+From over-the-air (OTA) firmare updates, to remote procedure calls (RPC) and
+device fleet settings, to device-to-cloud time series data and bidirectional
+state data, we've already built the management tools you need. Our data-routing
+features ensure your data can go where you need it, whether that's AWS, Azure,
+GCP, or any other server, app, or database platform.
+
+### Device Side
+
+You choose your own embedded hardware and firmware platform. Golioth already
+provides SDKs for Zephyr, ESP-IDF, and ModusToolbox™. For other platforms,
+we have a [porting
+guide](https://github.com/golioth/golioth-firmware-sdk/blob/main/docs/Porting_Guide.md)
+and can offer guidance in that process.
+
+## Let's get Started!
+
+The getting started guide will prepare your Golioth account to communicate
+directly with your hardware devices, and guide you through flashing demo
+applications onto your hardware so you can begin testing Golioth services right
+away.
+
+In this section:
+
+* Open your Golioth account and create your first device.
+* Flash a pre-compiled binary or build some sample app firmware from source.
+* See your device connect to Golioth, send and receive data, and control this
+  mighty mini-fleet from the cloud.